ST’s new ParaScan Tunable Integrated Capacitors (STPTIC) are electrically adjustable to maintain efficient transfer of energy from the handset amplifier to the antenna under various operating conditions.
The STPTIC helps maximise radiated RF power for better call performance and overcome the challenges of use in multiple frequency bands when the handset is held close to the user’s ear or moved away, while minimising amplifier power consumption for longer battery life.
Unlike alternatives that typically contain multiple switched capacitors, the STPTIC allows capacitance to be adjusted smoothly without steps for greater precision. The compact STPTIC combines a single, variable capacitor with control circuitry using ST’s Integrated Passive and Active Device (IPAD) technology.
According to Ricardo De-Sa-Earp, Group VP and General Manager, Application-Specific Discretes & IPAD Division, the STPTIC family delivers an even more compelling option for future 4G LTE handsets, which will demand high wireless performance for reliable voice and high-speed data communications along with longer battery life.
He added that two of the world’s top five handset manufacturers have already chosen this technology for antenna matching in their current handsets.
The advanced generation of ParaScan Barium Strontium Titanate (BST) variable-capacitor technology from the STPTIC family meets the demands of wireless system designers by displaying high Q factor at frequencies up to 2.7 GHz, more than 3:1 capacitance change with varying control voltage, and stable performance over the specified temperature range. Devices are easy to design-in, requiring only minimal external components, and have high power capability meeting the requirements of the GSM standard.
Key features of the STPTIC family of capacitors:
- Range of capacitance values: 2.7 to 8.2 pF
- High power capability (+36 dBm)
- High tuning range (3.5:1)
- High linearity device (IP3 > 60dB)
- High quality factor (Q factor) up to 2.7 GHz
- Low leakage current (less than 100 nA)
- Compatible with ST antenna tuning circuit (STHVDAC series)